The present invention relates generally to a manner by which to assign channels for communications between mobile stations and a fixed site transceiver of a radio communication system, such as a WLAN (Wireless Local Area Network) system. More particularly, the present invention relates to apparatus, and associated method, by which to allocate channels in which the fixed-site transceiver and the mobile stations are operable pursuant to the Bluetooth, or other, standard. Greater numbers of mobile stations are permitted to communicate with the fixed-site transceiver than the limited number of mobile stations otherwise conventionally permitted to form a single piconet together with the fixed-site transceiver.
New types of communication systems have been made possible as a result of advancements in communication technologies. Such new types of communication systems have generally permitted increased rates of data transmission or have provided more convenient manners by which to transmit data.
Advancements in communication technologies have, for instance, permitted the introduction, and popularization, of new types of radio communication systems. In a radio communication system, a communication channel formed between sending and receiving stations of the radio communication system are defined, at least in part, upon a portion of the electromagnetic spectrum. Because a wire line connection is not required to be formed between the sending and receiving stations, increased mobility is inherent in a radio communication system. That is to say, a communication station of a radio communication system is repositionable from one location to another while still permitting communications to be effectuated therethrough. And, communications are generally also possible as the communication station is moving. Mobile stations operable in a cellular communication system, for instance, permit communication therethrough as the mobile station is moving.
Various communication standards have been promulgated and communication devices operable in compliance with such standards have been developed. A so-called Bluetooth standard, for instance, has been promulgated in which operational requirements of a BLUEPAC (Bluetooth Public Access) communication system are set forth. Communication signals generated during operation of a BLUEPAC communication system are generally of low power levels transmitted at high-frequencies. The communication range of a Bluetooth device is relatively small, e.g., in the range of 10 m.
Proposals have been set forth to utilize Bluetooth technologies in WLAN (Wireless Local Area Network) systems. A WLAN system is operable in manners analogous to operation of a conventional, wired LAN (Local Area Network) system, but also utilize mobile stations connectable to the LAN by way of radio links.
Access points form portions of the network of a WLAN. An access point is a fixed-site transceiver capable of communicating with the mobile stations by way of radio links formed therebetween.
While access points defined in WLANs constructed pursuant to other communication standards, such as the HIPERLAN/2 (High Performance Local Area Network) permits a relatively large number of mobile stations to communicate with a single access point, an access point operable pursuant to the Bluetooth standard is not generally capable of communicating with any more than a small number, e.g., seven, mobile stations. In a HIPERLAN/2 system, MAC-ID and DLCC-ID values are utilized to identify communication stations. A MAC-ID is often an eight-bit length, and a DLCC-ID is of a six-bit length. Utilization of HIPERLAN/2 devices as access points are able to communicate with a number of mobile stations related to the bit-length of the identifier used to identify the mobile stations related to the bit-length of the identifier used to identify the mobile stations, either eight bits or six bits.
An identifier used to identify a Bluetooth device, in contrast, is of a bit length of only three bits. And, responsively, a Bluetooth-compatible device forming an access point is capable of communicating with only seven mobile stations in separate communications, i.e., communications which are other than a multi-cast communication.
This limitation limits the usefulness of Bluetooth-compatible devices to form access points in a WLAN as greater than seven mobile stations must be capable of operation with a single access point in a practical implementation of a WLAN system.
If a manner by which to increase the number of mobile stations which can communicate with a single Bluetooth-compatible access point could be provided, a Bluetooth-based WLAN system would be better able to be implemented.
It is in light of this background material related to radio communication systems that the significant improvements of the present invention have evolved.
The present invention, accordingly, advantageously provides apparatus, and an associated method, by which to assign channels for communications between mobile stations and a fixed-site transceiver of a radio communication system.
Through operation of an embodiment of the present invention, a large number of mobile stations are permitted to communicate with the fixed-site transceiver. When the fixed-site transceiver forms an access point of a WLAN (Wireless Local Area Network) system, existing limitations in the number of mobile stations capable of concurrently communicating with the access point are obviated if the access point is constructed pursuant to an embodiment of the present invention.
In one aspect of the present invention, a manner is provided by which to allocate channels in which the fixed-site transceiver and the mobile stations are operable pursuant to the Bluetooth, or other, standard. A Bluetooth-compatible access point formed of the fixed-site transceiver is capable of communicating with more than seven mobile stations. Seven is the maximum number of mobile stations, together with the access point, which can form a piconet, as defined in the Bluetooth standard. A plurality of piconets are formed, thereby to permit the additional numbers of mobile stations to communicate with the access point.
In another aspect of the present invention, Quality of Service (QoS) levels are associated with each of the mobile stations, at least pursuant to a selected communication service. Indications of the mobile stations together with the QoS levels associated therewith form a database stored at a storage device accessible by the access point. Piconets are defined to include mobile stations having common QoS levels associated therewith. That is to say, the mobile stations positioned within the coverage area encompassed by the access point are segregated according to the QoS levels associated therewith. In other words, one piconet is mapped into one QoS level. Mobile stations operable at QoS levels of different values are assigned to different piconets.
In another aspect of the present invention, mixed traffic per piconet is utilized. A piconet to which mobile stations exhibiting a selected QoS level are also permitting of mobile stations operable pursuant to a lesser QoS level. Communication services are effectuated with mobile stations which require the higher QoS level prior to permitting communications with mobile stations which have associated therewith the lower QoS levels. By permitting mixed traffic per piconet, greater channel efficiencies are achievable.
In another aspect of the present invention, a hopping pattern is provided for communications with mobile stations assigned to different ones of the piconets. Mobile stations assigned to a piconet have clocks which are synchronized to the clock of a master defined in each of the piconets. The clocks of all of the mobile stations in the piconets are adjusted to correspond to the clock of a master assigned to the piconet, but offset by a selected amount. Different ones of the piconets are offset by different timing periods so that different clock timing is exhibited in the different piconets.
In one implementation, the access point and mobile stations are operable pursuant to the Bluetooth standard which provides for short range, radio communications between communication stations, such as between the mobile stations and the access point. Piconets are defined pursuant to the Bluetooth standard in which one master device and up to seven slave devices are permitted to form a piconet. Each of the mobile stations has associated therewith a QoS level at which communications pursuant to a least one communication service are to be effectuated. In other words, one piconet is mapped into one QoS level. As any communication station, formed either of an access point or a mobile station, can form a master device for a piconet, a large number of piconets, and correspondingly large numbers of mobile stations, can be associated with a single access point to permit communications therewith. Thereby, a manner is provided by which to permit increased numbers of mobile stations to communicate with a Bluetooth-compatible access point in a WLAN system.
In these and other aspects, therefore, apparatus, and an associated method, is provided for a radio communication system in which a plurality of mobile stations communicate by way of radio links with a fixed-site transceiver. A scheduler allocates communication channels upon which to permit communications between the fixed-site transceiver and selected ones of the plurality of mobile stations. A storage device is coupled to the fixed-site transceiver. The storage device stores indications of identities of the plurality of mobile stations together with quality levels at which selected communications therewith are to be effectuated. An assignor is coupled to the storage device and is capable of retrieving the indications stored thereat. The assignor is selectably operable to define at least a first set of mobile stations of the plurality of mobile stations. The first set of mobile stations has a maximum number, or fewer, of mobile stations. The assignor assigns a communication channel upon which communications between the mobile stations of at least the first set and the fixed-site transceiver are to be effectuated.
A more complete appreciation of the present invention and the scope thereof can be obtained from the accompanying drawings which are briefly summarized below, the following detailed description of the presently-preferred embodiments of the invention, and the appended claims.